1. Field of the Invention
The invention relates to a switch, more particularly to a rolling-ball switch that may be suitably mounted on a circuit board for providing triggering signals.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional switch 10, as disclosed by the applicant in Taiwanese Patent No. 155965, includes a housing, a conductive ball 12, and four terminal rods 14.
The housing includes a bottom seat 13 and a top cover 11. The bottom seat 13 is made of plastic, and has top and bottom surfaces, and four spaced-apart through holes 131 extending through the top and bottom surfaces. Each through hole 131 is defined by four interconnected hole walls 132. The top cover 11 is made of plastic, and has a top wall 111, and four interconnected side walls 112 extending downwardly from a peripheral end of the top wall 111. The top wall 111 and the side walls 112 cooperatively define a chamber 113 having a bottom opening 114.
Each of the terminal rods 14 has an inner end 141 located within the chamber 113, an outer end 142 located outwardly of the bottom seat 13, and four interconnected lateral surfaces 143 extending between the inner and outer ends 141, 142.
The conductive ball 12 is disposed in the chamber 113, and is movable toward the inner ends 141 of the terminal rods 14 so as to place the switch 10 in an “ON” state, or away from the inner ends 141 of the terminal rods 14 so as to place the switch 10 in an “OFF” state.
During assembly, the bottom seat 13 is inserted into the chamber 113 so as to close the bottom opening 114 and thereby confine the conductive ball 12 within the chamber 113. The terminal rods 14 are then inserted respectively and interferentially into the through holes 131 by a jig (not shown) so as to position the terminal rods 14 in the respective through holes 131. The outer ends 142 of the terminal rods 14 are inserted respectively through slots 21 in a circuit board 20, after which the terminal rods 14 are soldered to the circuit board 20, thereby mounting and positioning the switch 10 on the circuit board 20. The switch 10 is tilted or turned so as to shift from an OFF state to an ON state, and vice versa.
Although the aforementioned conventional switch 10 can achieve its intended purpose, since the lateral surfaces 143 of the terminal rods 14 are smooth, connections between the lateral surfaces 143 of the terminal rods 14 and the hole walls 132 of the through holes 131 are weak and unstable.